Centrifugal casting apparatus



P. J. KAVENY CENTRIFUGAL CASTING APPARATUS Original Filed A ril 50, 1952 June 25, 1957 8 Shees-$heef 1 INVENTOR PAUL J. KAVEN June 25, 1957 P. J. KAVENY 2,796,643

CENTRIFUGAL CASTING APPARATUS Original Filed April 50, 1952 8 Sheets-Sheet 2 INVENTOR PAUL J. KAVENY June 25, 1957 P. J. KAVENY 2, 6,

CENTRIFUGAL CASTING APPARATUS v Original Filed April 30, 1952 8 Sheets-Sheet 3 INVENTOR PAUL .J. KAVENY June 25, 1957 P. J. KAVENY 2,796,643

CENTRIFUGAL CASTING APPARATUS Original Filed April 30, 1952 Y 8 Sheets-Sheet 4 INVE NTOR PQUL J. KAVENY xi i June 25, 1957 P. J. KAVENY CENTRIFUGAL CASTING APPARATUS Original Filed April 30, 1952 8 Sheets$heet 5 IIIJJIIJ 7V E 0 is Rm m O O L O mK v I "m mL 0 is 0 0 m W x 7? I mm I L 1 T F. J 1 lniln H. E E. 4.6 SQ NEW. 1 WS b0 QWNI 1 2 H June 25, 1957 P. J. KAVENY 2,795,643

CENTRIFUGAL CASTING APPARATUS Original Filed April 50, 1952 s Sheets-Sheet w 0 O Q i o o o 53 O Q 6': 6'; 5a

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INVENTOR PAUL J. KAVENY June25, 1957 r P. J. KAVENY 2,795,643

CENTRIFUGAL CASTING APPARATUS Original Filed April 30, 1952 8 Sheets-Sheet 7 gnnnnn United States CENTRIFUGAL cAsrrNG APPARATUS Continuation of application Serial No. 285,213, April 30, 1952. This application February 14, 1956, Serial No. 565,367

12 Claims. (Cl. 22-20) This invention relates to centrifugal casting apparatus. It relates especially to centrifugal casting apparatus comprising a rotatable flask open at both ends and a mold forming mandrel mounted for introduction into the flask from one end. Such apparatus is adapted for the centrifugal casting of hollow elongated objects such as lengths of pipe. I

Apparatus of the general type above referred to is disclosed in United States Patent No. 2,449,900. However, the apparatus of said patent is not adapted for the centrifugal casting of double hub pipe, i. e., lengths of pipe each having an enlargement in the form of a hub or hell at each end thereof. There is substantial demand for double hub pipe which prior to the present invention could be made only by the use of apparatus of a different type and far less efficiently than single hub pipe can be made utilizing the apparatus of said patent.

I have devised apparatus which is in some respects quite similar to the apparatus of said patent but in other respects entirely different and which makes possible the centrifugal casting of double hub pipe with virtually the same efficiency as can be attained in the casting of single hub pipe using the apparatus of said patent.

When single hub pipe is to be centrifugally cast the mold forming mandrel which is mounted for introduction into the flask from one end thereof may be provided with an enlargement or hub at the end of the mandrel which is the trailing end as the mandrel moves into the flask to impress in compacted mold forming material in the flask an enlargement for forming the single hub. After the mold of compacted mold forming material has been formed the mandrel may be withdrawn by moving it lengthwise out of the flask inthe direction opposite the direction in which it moved when entering the flask. A core may then be positioned in the enlargement in the mold whereupon the molten material, e. g., cast iron, to be centrifugally cast into a length of pipe may be introduced into the mold and the flask rotated to form the pipe.

When double hub pipe is to be made it is necessary to provide an enlargement in the mold at each end of the flask. It is not possible to form an enlargement in the mold at the end of the flask opposite the end from which the mandrel is inserted by use of an enlarged portion on the forward or free end of the mandrel as then it would not be possible to withdraw the mandrel through the mold after compacting the mold forming material without damaging the mold. In the use of other types of apparatus in which pipe is formed less efficiently than it can be formed by the use of apparatus of the type now in question enlargements can be made in the mold adjacent both ends, but problems quite diiflcult of solution are presented in adapting apparatus such as the apparatus of said patent for the centrifugal casting of double hub pipe.

It is necessary to provide for forming an enlargement in the mold at the end of the flask opposite the end from which the mandrel is introduced while at the same time atent 0.

of the mandrel and also for relative movement transverse- 2,796,643 1 Patented June 25, 1957 ly of the flask between the flask on the one hand and the mandrel and the mandrel support on the other hand to compact the mold forming material in the flask. In addition means must be provided for positioning a core in the end of the flask opposite the end from which the mandrel is introduced as well as in the end of the flask from which the mandrel is introduced.

It is necessary to simultaneously position in the end of the flask opposite the end from which the mandrel is introduced a hub to form an enlargement in the mold at that end of the flask and a support for supporting the free end of the mandrel. After the mandrel, mandrel support and hub on the one hand and the flask on the other hand have been relatively moved transversely of the flask to compact the mold foming material the mandred support and hub must be quickly removed to a position remote from the flask so that the core may be introduced.

I provide a carrier mounted adjacent the end of the flask opposite the end through which the mandrel is introduced, the carrier carrying a plurality of instrumentalities respectively selectively cooperable with the mandrel and flask. The carrier may carry a mandrel support and a hub, and preferably the hub is separate from the mandrel support so that it may be withdrawn from use when single hub pipe is to be made. The hub when in operative position is adapted to be engaged by the forward portion of the mandrel when the mandrel is introduced into the flask, the hub having a portion of greater diameter than the forward portion of the mandrel adapted to lie within the flask to form therein an enlargement in the mold. The carrier also may have therein an opening which in one position of the carrier may be substantially aligned with the flask through which means for delivering into the flask molten material to be centrifugally cast in the mold may be introduced. A core holder is preferably removably attached to the carrier at said opening for use when double hub pipe is to be made but withdrawable from use when single hub pipe is to be made, the core holder having an opening therethrough cooperable with the opening in the carrier to receive the means for delivering into the flask the molten material to be centrifugally cast in the mold.

The carrier is mounted for movement relatively to the flask transversely of the flask along with the mandrel to provide for compacting of the mold forming material in the flask. The carrier is also mounted for movement relatively to the flask axially of the flask since the hub carried by the carrier and the core holder carried by the carrier must each when being moved into operative position relatively to the flask enter the end of the flask opposite the end through which the mandrel is introduced.

The carrier must also be mounted for movement to selectively dispose the respective instrumentalities in position generally facing the end of the flask so that the respective instrumentalities may be introduced into the flask upon relative movement axially of the flask between the flask and the carrier. I preferably mount the carrier for turning movment so that it may be turned selectively to positions in which the respective instrumentalities are disposed to generally face the end of the flask.

In compacting the mold forming material in the flask to form the mold there must he relative movement transversely of the flask between the flask as a unit on the one hand and the mandrel and mandrel support as another unit on the other hand. Such relative transverse movement may be efiected by moving the flask while holding the mandrel and mandrel support in position but I prefer to maintain the flask in position and to move the mandrel and mandrel support relatively to the flask. In either case the flask rotates while the mold forming material is being compacted therein. I prefer to provide separate means respectively moving the mandrel and the mandrel parallel and coplanar.

nen ss support transversely of the flask. Stop means which may be adjustable are preferably provided to limit the extent of relative transverse movement between the flask on the one hand and the mandrel and mandrel support on the other hand. Likewise adjustable "stop means are preferably provided for limiting the relative movement of the respective elements longitudinally of the flask.

' My apparatus embodies numerous other hovel features which contribute to its utility and'efliciency. I have made no attempt in this preliminary introductory portion of the specification to catalogue all of the improvements embodied in my apparatus. Other details, objects and advantages of the invention will become apparentras the following description of a present preferred embodiment thereof proceeds. i

In the accompanyingdrawingsl have shown a present preferred embodiment of the invention in'which Figure 1 is a plan view 'ofcentrifugal casting apparatus, the lower half of the apparatus as shown in that figure being adapted for the casting of single hub pipe and the upper half being adapted for the casting of double hub' pipe; V a i Figure 2 is a side elevational' view of the apparatus adapted for the casting of double hub pipe;

Figure 3 is an end elevational view of the apparatus as shown in Figure 1 as viewed from the left hand end of that figure; I

Figure 4 is a' fragmentary view of the apparatus partly in transverse cross section on the line IV IV of Figure l and partly'in end elevation;

Figure 5 is a view similar to Figure 4, the part of Figure 5 .in' transverse cross section being taken on the line VV of Figure 1 in the same plane as the part of Figure 4 intransverse'cross section; a

Figure 6 is a somewhat diagrammatic elevational view of a portion of the apparatus shown in Figure 5 looking from right toward left in Figure 5;

Figure 7 is a fragmentary longitudinal cross sectional View such as would be taken on the line V II-VII of Figure 1 but with the mold forming mandrel and the mandrel support in operative or advanced positions;

Figure 8 is a view similar to the upper portion of Figure 7 but showing the apparatus set up for the making of single hub pipe;

Figure 9 is a fragmentary longitudinal cross sectional view through a portion of the apparatus taken on the line IX'IXof Figure l; and

Figure 10 is a fragmentary longitudinal cross sectional view through a portion'of the apparatus taken on the line XX ofFigure 5. 7

Referring now morefparticularly'to the drawings, the apparatus is mounted upon a base 2 and comprises a flask cradle/3 having coaxi'al'trunnions 4 mounted for turning movement in bearings 5 so that the cradle 3 is mountedfor. turning movement in a vertical plane perpendicular to the common am's of the trunnions 4.

Thev cradle 3 may carry any desired number of rotatable flasks in side-'by-side relationship with their axes In the structure shown the cradle 3 carries'four flasks 6. Each of the flasks 6 has its own driving motor 7 mounted in the cradle beneath the flask, each of the driving motors driving its flask through a suitable driving connection such for example as a series of V-belts trained about pulleys on the flask and motor shaft respectively. a

Connected with the cradle are two brackets 8 to each of which is pivotedat 9 a piston rod 10 carrying a piston operable within a cylinder 11 pivoted at 12 to a bracket 13 carried by the'base 2. Means are provided for admittingfluid under pressure to the cylinders 11 selectively at opposite sides of the pistons therein for swinging the cradle 3 between a position as shown in the drawingsin which the axes of the flasks are generally horizontal and flasks are generally upright. The base 2 carries two pedestals 28 respectively cooperating with positioning members 29 carried by the cradle 3 to accurately position the cradle in the position in which it is shown in the drawings with the axes of the flasks generally horizontal. When the cradle is swung to the position in which the axes of the flasks are generally vertical two pads 30 on the cradle engage stop members 31 on the base 2 to limit turning movement of the cradle and position it at head. The core holders 19 are respectively disposed with 7 their axes in the same longitudinal vertical'planes as the axes of the flasks 6.

Mounted atop each of the brackets 14 and pivoted thereto at 20 is a cylinder 21 within 'which operates a piston-whose piston rod 22 is pivoted at 23 to a projection 24 carried by the core holder support 16. Means are provided for admitting fluid under pressure within the cylinders 21 to turn the core holder support 16 about the common axis of the pivots 15 between a position in which the core holders 19 are coaxial with the flasks 6 and a position in which the core holders 19 are swung out of coaxial relationship with the flasks as indicated in chain lines at 25 in Figure 2. Fluid under pressure is admitted within the cylinders 17 to move the core holders 19 into and outof the ends of the flasks 6 when the core holders are coaxial with the flasks. When the core holders are swung up to the chain line position indicated at 25 in Figure 2 the core holder support clears the ends of the flasks to permit entry thereinto of mandrels presently to be described whose function is to form and compact in the flasks mold forming material, such, for example, as sand, to make in the flasks molds for the centrifugal casting of lengths of pipe. The structure and operation 7 of the core holdersupport 16 and the core holders 19 do not constitute the present invention, being claimed in Patent No. 2,729,865.

Pivoted to the'cradle 3 about a common axis 26 are mold Stampers 27, one for cooperation with each of the four flasks, for stamping in the mold formed in the flask data to be cast in the pipes, the stampers and their operating mechanism being covered in copending applica tion Serial No. 206,690, filed January 18, 1951.

The present invention is not concerned with the operations which are performed whenthe cradle is in position with the axes of the flasks generally upright. However, it may be remarked that, similarly to the apparatus of Patent No. 2,449,900, the cradle is swung to position the flasks with their axes generally upright with the bottoms of the flasks closed by the core holders 19 but without any cores thereon while the flasks are being filled with mold forming material. Thereupon the cradle is turned to position the flasks with their axes generally horizontal as shown in the drawings and the flasks are rotated to cause the mold forming material by centrifugal action to be somewhat consolidated against the inner walls of the flasks, forming within each incipient mold a generally central longitudinal opening through which a mandrelpresently to be described is inserted to further compact the mold forming material and shape the mold.

Carriedby the base 2 are parallel longitudinal rails 32 which project somewhat to the right of the base 2 viewing Figures 1 and 2 and have their ends supported at 33. Mounted for movement along therails 32 is a carriage 34 having wheels 35 riding atop the rails 32 and rollers 36 engaging the inner faces of the rails to accurately position the carriage transversely of the rails. The carriage'34 is moved along the rails by a piston operating in a cylinder 37, the piston rod 38 being connected by a pin 39 to a bracket 40 connected with the under side of the carriage. The cylinder 37 is supported by a supporting structure 41. Forward movement of the carriage, i. e., movement toward the left viewing Figures 1 and 2, is limited by adjustable stops 42. Rearward movement of the carriage, i. e., movement toward the right viewing Figures 1 and 2, is limited by the piston in the cylinder 37 reaching the end of its stroke.

Mounted on the carriage 34 for movement transversely thereof is a mandrel support 43. At each end the mandrel support 43 has two horizontal parallel projecting pins 44 entering sockets 45 carried by the carriage. The four pins 44 operating in the respective sockets 45 insure controlled transverse movement of the mandrel support 43 while the mandrels presently to be described which are carried by the support are maintained at all times with desired orientation. The carriage 34 carries an adjustable stop member 46 shown as being in the form of a bolt which is maintained in its adjusted position by nuts 47. The mandrel support 43 is urged toward the stop 46 by a compression coil spring 48. The stop member 46 is adjusted so that when the mandrel support is in position thereagainst as shown in Figure 1 the mandrels now to be described have their axes respectively in the vertical planes containing the axes of the flasks 6.

The mandrel support 43 has four sets of aligned bearings 49 in each of which is rotatably supported a mandrel 50. Each mandrel 50 has a rearward portion 51 disposed within the bearings by which the mandrel is rotatably supported and an enlargement or hub 52 for forming in the mold at one end of the flask an enlargement wherein a hub at one end of the pipe length cast in the mold is formed.

The forward end of each mandrel 50 is designed to selectively accommodate means for use when single hub pipe is being cast and means for use when double hub pipe is being cast. Referring to Figures 7 and 8, the forward end of each mandrel 50 has a reduced portion 53 forming with the body of the mandrel a shoulder 54. Beyond the reduced portion 53 is a further reduced portion 55. A sleeve is introduced over the portion 55 and the portion 53 so as to abut against the shoulder 54, the shape of the sleeve being determined by whether single hub pipe or double hub pipe is to be cast. In Figure 7 the sleeve is designated 56 and has an enlarged portion 57 whose extremity engages the shoulder 54 and which fits snugly about the portion 53 of the mandrel and a reduced portion 58 which fits snugly about the portion 55 of the mandrel. The outer surfaces of the portions 57 and 58 are cylindrical, the outer surface of the portion 57 being of the same diameter throughout as the outer surface of the body of the mandrel 50. The sleeve 56 is held in place on the mandrel by a cap 59 fitting snugly over the end of the portion 55 and maintained in place by a stud 60 threaded into the end of the mandrel and passing through a bore 61 in the head of the cap, a holding nut 62 being threaded onto the stud 6t) and bearing against the end of the cap.

A sleeve 56 is used on each mandrel 56 when double hub pipe is being cast as will presently be explained. When single hub pipe is being cast each sleeve 56 is replaced by a sleeve 63 shown in Figure 8. The sleeves 63 differ from the sleeves 56 in that each sleeve 63 has an annular outward projection 64 at the left-hand extremity of the larger portion of the sleeve, the projection 64 being for the purpose of forming in the mold a depression for casting the spigot at the end of a length of single hub pipe opposite the end at which the hub or bell of the pipe is disposed. Likewise the portion of the sleeve 63 to the left of the projection 64 viewing Figure 8, which portion is designated 65, is of smaller external diameter than the portion 58 of the sleeve 56. This is to insure formation in the mold of an adequate dam beyond the depression in which the pipe spigot is formed so that the molten material of which the pipe is being cast will not' flow out of the end of the mold.

The base 2 carries adjacent the left-hand ends of the flasks viewing Figures 1 and 2 parallel rails 66 on which rails 66 and rollers 69 engaging the inner faces of the rails to position the carriage transversely of the rails for accurate movement therealong.

Carried by the base 2 substantially at the longitudinal center line thereof is a cylinder 70 arranged with its axis generally horizontal and generally parallel to the length of the apparatus in which operates a piston whose piston rod 71 is connected at 72 to a downwardly projecting bracket 73 carried by the carriage 67. Thus operation of the piston in the cylinder 70 causes movement of the carriage 67 along the rails 66. Movement of the carriage toward the right viewing, for example, Figure 7 is limited by a pair of adjustable stop members 74 which engage portions 75 of the base 2. Movement of the carriage 67 in the opposite direction is limited by the A pair of flexible tension elements shown as being in the form of chains 76 are each connected at one end at 77 to the carriage 67 and at the other end at 78 to an adjustable connector 79 carried by a bracket 80 connected to the base 2. The chains 76 are slack when the carriage is in its outward position, i. e., the position toward the left viewing Figures 1 and 2, in which the carriage is relatively remote from the cradle 3. When, however, the carriage is moved toward the cradle 3 and the flasks 6 carried thereby the chains 76becorne taut at the time when the adjustable stop members 74 engage the portions 75 of the base 2. Thus the chains act as tension struts resisting forces tending to tilt the carriage toward the left viewing Figure 9. Such forces may be applied to the carriage when the mandrels come into engagement with means presently to be described which are carried upon the carriage. Employment of the chains 76 has an advantage over the use of hold-down rollers engaging the bottom surfaces of the tracks 66 as use of such holddown rollers would promote binding in the event, for example, that mold forming material should come to rest upon the tracks.

The carriage 67 is of generally U shape as shown in Figure 3 and carries at one side a bracket 81 having there in a bearing 82. At the other side of the carriage 67 has a bracket 83 having therein a bearing 84. The bearings 82 and 84 are coaxial. Mounted in the bearings 82 and 84 is a carrier S5. The carrier has a trunnion 86 disposed in the bearing 82 and a trunnion 87 disposed in the bracket 92. Each bearing bracket 92 has opposed flange portions 93 through which it is bolted by bolts 94 to the carrier. Disposed within each bearing bracket 92 is a bearing unit 95 of any suitable type, such, for example, as a Dodge bearing unit comprising a housing having bearing means therein. Each bearing unit 95 may be maintained within its bearing bracket 92 by being pressed therein. Each bearing unit 95 has a generally cylindrical opening therethrough as known to those skilled in the art for receiving a rotatable machine part.

I provide for rotatably mounting in each of the bearing units 95 a rotating part whose form is determined by whether the pipe being cast is single hubpipe or doublehub pipe." The rotatingpart is in the'form of a flanged sleeve 96 serving as a pilot or mandrel support as shown in Figure 8 when single hub pipe is being cast; The flange of'the pilot isdesignated 97 and serves as a 'guard to prevent mold forming material from getting'into the bearing unit. 'The bore of the pilot is such as to'snugly and guidingly receive the mandrel cap 59 as shown in Figure 8. The mouth of the pilot bor'e is somewhat enlarged or beveled as shown at 98 to facilitate entry ofthe end of the mandrel thereinto. The pilot supports the end of the mandrel While the mandrel is performing its mold forming function. V 7

When double hub pipe is being; castthe pilot- 96 is replaced by a combination pilot and hub Q9 as shown in Figure 7. :The' combination 'pilot and hub 99 may be formed in one piece as shown or in two pieces bolted or otherwise fastened together. The hub portion is designated 100 and projects axially from the'pilot portion as shown inFigure 7. The hub 1titlis adapted to be engaged by the forward portion of the mandrel when the mandrel is introduced into-the flask and to lie within the flask to form'th'erein an enlarged end of a mold of compacted mold forming material to formone of the hubs on the pipe being cast. The nose of the hub 100 is tapered as shown at 191 and has a bore 102 of such size as'to snugly receive the portion 57' of the sleeve 56 as shown in Figur'e 7. The rearward portionof the hub 100 is hollowed and has passages 1193 to permit mold forming material pushed-into the hub by the :end of-the mandrel to be discharged centrifugally upon rotation of the mandrel and hub. V

The axial distance from the end of the mandrel to the tapered shoulder between the portions 57 and 58; of the sleeve 56 is greater than the axial distance between the extremity of thehub 1% and the mouth of the pilot. This is to insure thatthe mandrel will be in guided relationship to the pilot when the portion 57 of the sleeve 56 enters the hub 1% whereby to avoid damage to the hub.

In the position in which the carrier is shown in Figures 7 and 8 it has at the top four openings 88 disposed respectively with their centers approximately in the vertical longitudinal planes containing the axes of the four flasks 6. Each of the openings 83 is flanked on both sides by pads 8% for the application of a core holder when double hub pipe is to be cast. When single hub pipe is to be cast no core holder is used and the pads 89 are covered and'protected by cover plates 90.

As explained above the carrier 85 is turnable about the common axis of the trunnions 86 and 87; Its first angular position in the cycle of operations is that shown in Figures 7 and 8 in which the mandrel pilots are disposed substantially coaxially with the mandrels. After formation of the molds the carrier is adapted to be turned through an angle of 90 in the clockwise direction viewing Figures 7 and 8 to position the openings 88 in substantial alignment with the flasks, If single hub pipe is being cast pouring boots for introducing molten material to be cast in the molds are introduced through the then open top of the carrier and through the openings 88 to introduce the molten material into the flasks. When double hub pipe'is being cast a core holder 104 is rotatably mounted on the carrier 85 at each of the openings 88 by being bolted tothe carrier at the pads 89. As shown in Figure 7 each of the core holders has a hollow cylindrical core receiving portion 11. 5 through which the. pouring boot is adapted to be projected when the molten material to be cast is to be introduced into the mold. a i a V i' As shown in Figure 5the-trunnion 87 of the carrier 85 has a reduced extension'ritie into which is threaded at 166m a rod 1'97- which passes freely through a central bore; in'a speed reducer 198 mounted on the carriage 67 The speedreducer 108 is driven through a shaft'1tl9" carrying a sprocket 110 by a sprocket chain 111 drivenby a fluid motor l12 I i The trunnion extension ltlfi is of rectangular crosssectional shape as shown in Figure 6 and has mounted thereon opposed brackets 113 fastened together by bolts 11%, each bracket carrying a stud 115 on which is journaled a roller 116. The speed reducer 198 has a hollow shaft 117 through which the rod 197 passes, the hollow shaft 117 carrying a collar 118 having axially projecting lugs 119 in opposed pairs, each of the rollers 11'6being received between the lugs of one of such pairs of lugs. Thus turning of the speed reducer shaft 117 causes turning of the carrier 85 While at the same time providing for axial movement of the carrier 85 relatively to the speed bearing 129 and. a non-cylindrical terminal portion 130 projecting therefrom. The portion 130 has a flat face 131 operating against a guide 132 to prevent turning of the extension 127. The piston is normally urged outwardly or toward the left viewing Figure 10 by a compression coil spring 133 but may be retracted by admitting fluid'pressure to' the left of the piston through a port 134. The interior of the cylinder to the right of the piston viewing Figure 10 is open to the outside through a vent 135.

Within the cylinder is a stop member 136 which limits movement of. the piston toward the right viewing Figure 10. The extension 127 is sealed to the bearing 129' by an O- ring 137. a

The cylinders 123 and 124 are positioned so that when the respective piston extensions thereof are projected they are disposed in the path of the roller 121 as the carrier 85 turns about the axes of its trunnions. The cylinders 123 and 124 are positioned so that when their pistons are projected the carrieris stopped in desired angular positions. The cylinder 123' is positioned to stop the carrier in the angular position shown in Figures 7 and 8. The cylinder 124 is positioned to stop the carrier in an angular position turned 90 in'the clockwise direction from the position in which the carrier is shown in Figures 7 and 8. V

The trunnion 86 has an extension 138 having a threaded portion 139 on which is threaded a nut 14% having a ring 141 welded thereto. The ring 141 has an annular projection 142. The nut 14% is maintained in desired adjusted position on the threaded portion 139 by a lock nut 143. Disposed about the trunnion extension 138 is a bearing 144 into which the projection 142 extends and which is received within the outer end of a spring guide 145. A compression coil spring 1 56 is disposed about the extension 138 and bears at its left-hand end viewing Figure 4 against the spring guide 145 and at its right-hand end against a thrust washer 147 carried by the bracket 81. Thus the spring 146 urges the carrier 85 toward the left viewing Figure 4. a V

Disposed about the trunnion $6 is a bearing148 which with the parts in the position shown in Figure 4 lies between and in contact with each of the brackets 81 and the left-hand end of the carrier 85. Thus the bearing 148 limits movement of the carrier 85 to the left viewing Figure 4 due to the action of the spring 146 while providing for turning of the carrier relatively to the bracket 81.

When the mandrels are in their operative positions within the flasks 6 the .mandrels and the mandrel supports or pilots are moved transversely of the axes of theflasks to compact in the flasks the mold forming material disposed therein. This is true whether single hub pipe or double hub pipe is being cast. Provision is made 'for separately port and the carrier are both in their inward or operative positions. I provide two brackets 149 and 150 mounted upon the base 2. The bracket 149 carries a cylinder 151 disposed with its axis extending transversely of the apparatus and within which operates a piston having a piston rod 152 carrying at its extremity a pusher 153. The bracket 150 carries a cylinder 154 disposed with its axis extending transversely of the apparatus and within which operates a piston having a piston rod 155 carrying at its extremity a pusher 156. The cylinder 151 is disposed so that when the carrier 85 is in its inward or operative position the endof the trunnion extension 138 will be disposed in transverse alignment with the pusher 153. The cylinder 154 is disposed so that when the mandrel support 43 is in its inward or operative position the end of the stop member 46 will be disposed in transverse alignment with the pusher 156.

Mounted on the base 2 respectively opposite the cylinders 151 and 154 are brackets 157 and 158. Adjustably mounted in the bracket 157 is a stop member 159 which lies opposite the end of the rod 107 when the carrier 85 is in its inward or operative position. Adjustably mounted in the bracket 158 is a stop member 16% which lies opposite a projection 161 on the mandrel support 43 when the mandrel support 43 is in its inward or operative position.

I shall now describe a cycle of operations of my centrifugal casting apparatus. Initially the mandrel support 43 is in its extreme right-hand position viewing Figure 1 and the carrier 85 is in its extreme left-hand position viewing Figure 1 so as to permit the cradle 3 carrying the four flasks 6 to be turned about the common axis of the trunnions 4 to the position in which the flasks are generally upright. The core holders 19 are moved against the tlower ends of the flasks to close the flasks at their bottoms and prevent mold forming material introduced into the upper ends thereof from falling out. Mold forming material is introduced into the upper ends of the flasks. The flasks are rotated about their respective axes and the cradle 3 is turned about the common axis of the trunnions 4 to the position of Figures 1 and 2 in which the axes of the flasks are generally horizontal. The rotation of the flasks causes the mold forming material therein to be somewhat compacted or consolidated by centrifugal action against the inside walls of the flasks, thereby forming through the mold forming material in each flask a generally central passage.

The core holders 19 are withdrawn from the flasks by fluid pressure operating in the cylinders 17. Thereupon through fluid pressure operating in the cylinders 21 the core holder support 16 is turned about the common axis of the pivots to the position in which the core holders are disposed as indicated in chain lines at in Figure 2 so as to clear the flasks for entry thereinto of the mandrels 50.

Through fluid pressure acting in the cylinder 37 and with the mandrels maintained axially of the flasks by the spring 48 the mandrel support 43 carrying the mandrels is moved toward the left viewing Figures 1 and 2 so that the mandrels enter the openings in the partially consolidated mold forming material in the flasks. If single hub pipe is being cast each mandrel is provided with a sleeve 63 while if double hub pipe is being cast each mandrel is provided with a sleeve 56.

As the mandrels are introduced into the flasks the carrier 85 is in the position shown in Figures 7 and 8. If single hub pipe is being cast the carrier 85 is equipped as shown in Figure 8 while if double hub pipe is being cast the carrier 85 is equipped as shown in Figure 7. For present purposes it will be assumed that double hub pipe is being cast and the description will proceed accordingly. From the above description of the apparatus and from the present description of operation the steps employed in the formation of single hub pipe will be understood.

With the carrier oriented as shown in Figure 7 the carriage 67 is moved toward the right viewing Figures 1 and '2 by the operation of fluid under pressure in the cylinder 70. The movement of the carriage 67 to the right is limited by engagement of the stop members 74 with the portions 75 of the base 2. At the same time the movement of the mandrel support 43 toward the left is limited by the adjustable stop members 42. As the mandrels 50 and the hubs approach each other the reduced extremity of each mandrel passes freely through the corersponding hub until it enters into guided relationship With the pilot 99. After the front end of the mandrel has entered into guided relationship with the pilot 99 the portion 57 of the sleeve 56 enters the reduced extremity of the hub 100 until the mandrel, pilot and hub assume the relationship shown in Figure 7. While the respective mandrels and hubs are thus being introduced into the flasks and into cooperative relationship with each other the flasks are preferably rotating. After the mandrels and hubs reach the relative position shown in Figure 7 rotation of the flasks is continued, or, if the flasks have not been rotating, is commenced, and the mandrel support 43 and the carrier 85 are moved transversely by fluid under pressure in the cylinders 151 and 154 until such movement is limited by the stop members 159 and 160. Such transverse movement of the mandrels and hubs compacts the mold forming material in the flasks and forms the molds therein. While the molds are being thus formed the mandrels and hubs as well as the mandrel supports or pilots turn through their engagement with the mold forming material. Such turning is promoted by mounting of the mandrels and the pilots and hubs on anti-friction bearings.

After the molds have been formed as just described fluid pressure is released within the cylinders 151 and 154 and the springs 146 and 148 respectively return the carrier 85 and mandrel support 43 to their normal positions in which the respective mandrels and hubs are coaxial with the flasks. Thereupon the mandrel support 43 is moved back toward the right viewing Figures 1 and 2 to its original inoperative position and the carriage 67 is moved back toward the left to its original inoperative position.

As above mentioned, the motor 112 is a fluid motor which may operate continuously, exerting a constant torque through the speed reducer 108 upon the collar 118 and thus through the lugs 119 and the rollers 116 constantly tending to turn the carrier 85 about the common axis of its trunnions 86 and 87. When the carrier 85 is in the position shown in Figure 7 it is maintained in that position by engagement of the roller 121 with the piston in the cylinder 123. As explained above, axial movement of the carrier 85 is permitted since the rod 107 moves freely within the speed reducer 108 and the roller 121 rolls along the flat face of the extension of the piston operating in the cylinder 123. Also, the rollers 116 roll along the lugs 119.

After the carriage 67 has been withdrawn toward the left viewing Figures 1 and 2 to its inoperative position the piston in the cylinder 123 is withdrawn inwardly permitting the fluid motor 112 through the speed reducer 108 and the other mechanism above described to turn the carrier 85 in the clockwise direction viewing Figure 6. The piston in the cylinder 124 is projected into the path of the roller 121 and when the roller 121 strikes that piston turning movement of the carrier 85 stops, this time with the core holders 1114 in alignment with the flasks. Preferably cores have been applied over the core receiving portions of the core holders 104 while the carrier 85 is in the position of Figure 7. When the carrier is turned to the right viewing that figure through 90 as just described the cores are positioned ready for entry into the left-hand ends of the flasks 6. Thereupon the carriage 67 is moved toward the right viewing Figures 1 and 2 to position the coresrin the left-hand ends of the flasks. V

The core holder support 16 is swung back to the position of Figures 1 and 2 with thecore holders 19 ready to enter the right-hand ends of the flasks 6. Preferably while the core holders 19 are in the position indicated by chain lines at 25 in Figure 2 cores are applied thereto so that when the core holder support 16 is turned down,

to the position of Figures 1 and 2 the cores are ready to enter the flasks. The core holders 19 are moved toward the left viewing Figures 1 and 2pby the operationof fluid under pressure in the cylinders 17, thus positioning the cores on the core holders 19 in the right-hand ends of the flasks viewing Figures 1 and 2.

Pouring boots are introduced through the core holders 164 and molten material, such, for example, as iron or steel, to be cast into lengths of pipe is flowed into the molds through the pouring boots, the flasks at the same time being rotated at speeds such as to cause the molten material to form hollow lengths of pipe against the molds in the flasks. Rotation of the flasks is continued until the molten material has sufficiently solidified. Thereupon the core holders 19 and 104 are withdrawn, the cradle '3 is tilted to generally upright position and the pipe lengths formed in the flasks are ejected downwardly through the lower ends of the flasks by exerting pressure against the upper ends thereof. The parts are now in position for repetition of the cycle.

The method herein described in connection with the description of the apparatus is claimed in my copending application Serial No. 285,214, filed April 30, 1952. That method may be practiced by the apparatus herein disclosed and by apparatus of various other structures. This application is a continuation of my copending application Serial No. 285,213, filed April 30, 1952, now abandoned.

While I have shown and described a present preferred embodiment of the invention it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.

I claim:

1. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask, :a mold forming mandrel mounted for movement along the guide means for introduction into the flask from one end, a hub mounted adjacent the opposite endof the flask in position to be engaged by the forward portion of the mandrel when the mandrel is introduced into the flask, the hub having a portion of greater diameter than the forward portion of the-mandrel adapted to lie within the flask to form thereinan enlarged end of a mold of compactedmold forming material, and means supporting and mounting the mandrel and hub as a unit on the one hand and the flask as another unit on the other hand for guided relative movement transversely of the axis of the flask while the hub is engaged by the mandrel. V

2. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask, a mold forming mandrel mounted for movement along the guide means for introduction into the flask from one end, a hub mounted for movement along the guide means for introduction into the flask from the opposite end, the mandrel and.

hub being shaped to engage each other within the flask when both are introduced into the flask to cooperatively form in the flask a mold of compacted mold forming material having an enlarged end at the end of the flask at which the hub is disposed, and means supporting and,

mounting the mandrel and hub as a unit on the one hand andthe-flask as another unit on the other hand for guided relative movement transversely of the axis'of the flask while the hub is engaged by the mandrel.

3. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide track means extending generally parallel to the axis of the, flask, a mold forming mandrel mounted for movement along the guide track means and guided by the guide track means independently of the flask for introduction into the flask from one end, the mandrel having a mold forming portion and an extremity which is at the forward end of the mandrel when it is introduced into the flask of a smaller transverse size than the mold forming portion of the mandrel, a support for supporting the forward end of the mandrel having a socket for snugly receiving the mandrel extremity and a hollow hub carried by the support adapted to lie within the flask about a portion of the mandrel when the mandrel extremity is disposed within the socket, the end of the hub remote from the support being shaped to snugly receive part. of the mold forming portion of the mandrel, so that the mandrel and hub may cooperatively form in the flask a mold of compacted mold forming material having an enlarged end at the end of the flask at which the hub is disposed.

4. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask, a mold forming mandrel mounted for movement along the guide means for introduction into the flask from one end, a hub mounted adjacent the opposite end of the flask in position to be engaged by the forward portion of the mandrel when the mandrel is introduced into the flask, the hub having a portion of greater diameter than the forward portion of the mandrel adapted to lie within the flask to form therein'an enlarged end of a mold of compacted mold forming material, means for rotating the flask at centrifugal speed, means for moving the hub to a position remote from the flask out of alignment with the flask to permit introduction into the end of the flask of means for delivering into the flask molten material to be centrifugally cast in the mold and means supporting and mounting the mandrel and hub as a unit on the one hand and the flask as another unit on the other hand for guided relative movement transversely of the axis of the flask while the hub is engaged by the mandrel.

5. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask, a mold forming mandrel mounted for movement along the guide means for introduction into the flask from one end, a turnable carrier mounted adjacent the opposite end of the flask, a hub carried by the carrier positionable in one position of the carrier to be engaged by the forward portion of the mandrel when the mandrel is introduced into the flask,

the hub having an annular portion of greater diameter than the forward portion of the mandrel adapted :to lie within the flask about the forward portion of the mandrel to form therein an enlarged end of a mold of compacted mold forming material, and means for turning the carrier to move the hub to a position remote from the flask to permit introduction into the end of the flask of means for delivering into the flask molten material to be centrifugally cast in the mold.

6. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask, a mold forming mandrel mounted for movement aiong the guide means for introduction into the flask from one end, a carrier mountwhen the carrier is shifted toward the flask whereby to position the hub for engagement by the forward portion of the mandrel when the mandrel is introduced into the flask, the hub having an annular portion of greater diameter than the forward portion of the mandrel adapted to lie within the flask about the forward portion of the mandrel to form therein an enlarged end of a mold of compacted mold forming material, the carrier after being shifted away from the flask following formation of the mold therein to withdraw the hub from within the flask being turnable to move the hub to a position remote from the flask to permit introduction into the end of the flask of means for delivering into the flask molten material to be centrifugally cast in the mold.

7. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide track means extending generally parallel to the axis of the flask, mold forming members mounted for movement along the guide track means and guided by the guide track means independently of the flask for introduction into the flask from the respective ends thereof, the mold forming members being shaped to interengage each other within the flask to form in effect a single composite mold forming member projecting through both ends of the flask, and means mounting the mold forming members as a unit on the one hand and the flask as another unit on the other hand for relative movement transversely of the axis of the flask while the mold forming members are so interengaged.

8. Centrifugal casting apparatus for centrifugally casting double hub pipe comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask, mold forming members each having a hub portion mounted for movement along the guide means for introduction into the flask from the respective ends thereof, the mold forming members being shaped to interengage each other within the flask to form in effect a single composite mold forming member projecting through both ends of the flask and shaped to form in the flask out of compacted mold forming material a mold having enlarged hub portions at both ends with a relatively small body portion between and communicating with the hub portions and means supporting and mounting the mold forming members as a unit on the one hand and the flask as another unit on the other hand for guided relative movement transversely of the axis of the flask while the mold forming members are so interengaged.

9. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask, a mold forming mandrel mounted for movement along the guide means for introduction into the flask from one end, the mandrel having thereon adjacent its forward end as it is introduced into the flask a removable collar having an outward annular spigot cavity forming projection whereby the same mandrel with the collar applied forms a mold with a spigot cavity and with the collar removed forms a mold without a spigot cavity, and a support for receiving and supporting the forward end of the mandrel when it is introduced into the flask.

10. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask, a mold form ing mandrel mounted for movement along the guide means for introduction into the flask from one end, a carrier carrying a hub mounted adjacent the opposite end of the flask in position to be engaged by the forward portion of the mandrel when the mandrel is introduced into the flask, the hub having a portion of greater diameter than the forward portion of the mandrel adapted to lie within the flask to form therein an enlarged end of a mold of compacted mold forming material, the carrier being withdrawable from said position, a core holder also carried by the carrier and rotatable with respect to the carrier and when the carrier is withdrawn from said position positionable at the enlarged end of the mold to hold a core therein to cooperate with the mold in forming an enlargement at the end of the casting formed therein and means supporting and mounting the mandrel and carrier as a unit on the one hand and the flask as another unit on the other hand for guided relative movement transversely of the axis of the flask.

11. Centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask, a mold forming mandrel mounted for movement along the guide means for introduction into the flask from one end, a carrier mounted adjacent the opposite end of the flask and a mandrel support and a core holder carried by the carrier, the core holder being rotatably mounted on the carrier, the carrier being shiftable between a position in which the mandrel support is positioned to support the forward portion of the mandrel when the mandrel is introduced into the flask and a position in which the core holder projects into said opposite end of the flask to hold a core in said opposite end of the flask to provide for casting in the mold of a casting having an annular enlargement at said opposite end of the flask.

12. In centrifugal casting apparatus comprising a supporting structure, a flask open at both ends rotatably carried by the supporting structure, guide means extending generally parallel to the axis of the flask and a mold forming mandrel mounted for movement along the guide means for introduction into the flask from one end, the improvement which comprises a carrier mounted for turning movement adjacent the opposite end of the flask, the carrier carrying instrumentalities including a hub having an annular portion of greater diameter than the forward portion of the mandrel adapted to lie within the flask about the forward portion of the mandrel to form therein an enlarged end of a mold of compacted mold forming material respectively cooperable with the mandrel and flask, means for turning the carrier, means for stopping the turning movement of the carrier with a selected one of said instrumentalities generally in alignment with the mandrel and flask, means for moving the carrier generally parallel to the axis of the flask and means supporting and mounting the mandrel and carrier as a unit on the one hand and the flask as another unit on the other hand for guided relative movement transversely of the axis of the flask while the hub is engaged by the mandrel.

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